Possibly my favorite "technical" shirt. Very comfortable material and the extra "tuck in" length makes for a great fit. That, and it didn't smell bad after I ran in it then left it stuffed at the bottom of a laundry back for a week.

The Capilene 1 T shirt provides a great baselayer because it wicks so great. The construction is a tight knit which provides some wind resistance but also provides some sun protection. I wear it trail running almost year round. Good to wash the stink out with some Nikwax soap every once in a while.